Lubricant



Patented Apr. 6, i943 zaiaosi LUBRICANT Clarence M. Loanc, Hammond, Ind., and James W. Gaynor, Chicago, 111., assignors to Standard Oil Company, Indiana Chicago, 111., a corporation oi No Drawing. Application March 24, 1941, Serial No. 384,939

17 Claims.

The present invention relates to improvements in lubricating oils and more particularly to lubricants for internal combustion engines of the spark-ignition type and Diesel type which are not susceptible to deterioration and the formationof sludge, carbon, or varnish in such engines particularly upon and about the valves and rings thereof.

Many oils are not well suited for the lubrication of internal combustion engines because they are susceptible to deterioration under severe operating conditions. This results in the development of carbonaceous and/r resinous or similar varnish-like deposits in the engine and on and about the valves and rings thereof. These objectionable deposits frequently result in such sticking of valves or rings as to interfere seriously with the operation of the engine. I

It is an object of the present invention to provide a method of lubricating internal combustion engines which will materially inhibit the formation of carbon and/or resinous and varnish-like deposits in such engines. It is a further object of the present invention to provide an improved additive which when added in small amounts to lubricating oils will substantially inhibit the deterioration of such oils and the formation of sludge, carbon and/or varnish-like deposits which is attendant with the deterioration of such oils.

We have discovered that the foregoing objects may be attained by the addition of small amounts, namely, from about 0.001% to about 10.0% and preferably from about 0.01% to about 3.0% of the product obtained by the process comprising reacting a phosphorus sulfide with an aromatic hydrocarbon. Any suitable phosphorus sulfide may be employed such as, for example, P386, P4S3, P437, P4810, or preferably PzSs. Aromatic hydrocarbons such as benzene, naphthalene, anthacene, toluene, xylene, diphenyl and the like may be employed. We may also employ aromatic hydrocarbons having alkyl substituents, and characterized by having substantially no pour point depressing properties When added to wax-bearing lubricating oil.

We may also employ as the starting material the highly aromatic fraction of petroleum oils obtained, for example, in the catalytic reforming of petroleum oils. The polymer, boiling above the normal gasoline end point, produced in reforming naphthas in the presence of hydrogen by the use of cyclization catalysts such as chromia or molybdena on alumina is particularly suitable.

Any of these phosphorus sulfide-aromatic hydrocarbon reaction products may be readily prepared by mixing an aromatic hydrocarbon with a phosphorus sulfide, for example, P285, in amounts ranging from about 1% to about and preferably from about 5% to about 25%, and

a non-oxidizing atmosphere, such as nitrogen.

The reaction product, if containing excess phosphorus sulfide, may then be diluted with a suit able diluent such as hexane, filtered and the diluent removed from the filtrate by suitable means such as by evaporation or by distillation.

If desired,the reaction product may be further refined to remove any objectionable odors, if present, by blowing the reaction product with steam or nitrogen at a temperature of about 200-400 F. until the product is substantially free of the objectionable odor.

The phosphorus sulfide-aromatic hydrocarbon reaction product may be used as such or it may be further modified by forming a neutralized product. The phosphorus sulfide-aromatic hydrocarbon reaction product normally shows a titratable acidity. This titratable acidity is neutralized when the reaction product is treated with a basic reagent. The phosphorus sulfidearomatic hydrocarbon reaction product when neutralized with a basic reagent containing a metallic constituent is characterized by the presence or retention of the metal constituent ofthe reagent. Other metal constituents such as a heavy metal constituent may be introduced into the neutralized product by reacting the same with a salt of the desired heavy metal.

The term neutralized phosphorus sulfide-aromatic hydrocarbon reaction product as used herein means a phosphorus sulfide-aromatic hydrocarbon reaction product having at least about 1% of its titratable acidity reduced by the reaction with a basic reagent, and includes the neutralized phosphorus sulfide-aromatic hydrocarbon reaction products containing a metal constituent resulting from said neutralization or resulting from the reaction of a heavy metal salt with the phosphorus sulfide-aromatic hydrocarbon reaction product treated with a basic reagent.

The neutralized phosphorus sulfide-aromatic hydrocarbon reaction product may be obtained by adding to the acidic reaction product a suitable F. for a periodcontaining a heavy metal constituent such as.

for example, tin, titanium, aluminum, chromium, cobalt, iron and the like may be obtained by reacting a salt of the desired heavy metal with the phosphorus sulfide-aromatic hydrocarbon reaction product which has been treated with a basic reagent.

It will be understood that when the neutralization is accomplished with a polyvalent basic material, such as lime, a product having excess basicity may be obtained.

The neutralized .phosphorus sulfide-aromatic hydrocarbon reaction product may be prepared by treating the reaction product with a hydroxide, an oxide, or a carbonate of an alkali metal or an alkaline earth metal, and preferably with potassium hydroxide, sodium hydroxide or lime. This neutralization may' be carried out, preferably in a non-oxidizing atmosphere, by contasting the phosphorus sulfide-aromatic hydrocarbon reaction product, either as such or dissolved in a suitable solvent, such as naphtha, with a solution of the basic reagent, for example, potassium hydroxide dissolved in alcohol. alternative methodthe phosphorus sulfide-aromatic hydrocarbon reaction product may be treated with solid basic compounds, such as KOH, NaOH, NazCOs, Nal-ICOs, KHCOa, K2002, or CaO, preferably at an elevated temperature of irom about 100 F. to about 450 F. and preferably from about 300 F. to about 400 F. Neutralized reaction products containing a heavy metal constituent may be prepared by treating the neutralized reaction product with a salt of the desired heavy metal.

The phosphorus sulfide-aromatic hydrocarbon reaction product or the neutralized reaction product per se may be used in lubricating oils, or they may be employed in combination with each other. A much improved lubricant is obtained when small amounts, for example, from about 0.001% to about 10%, and-preferably from about 0.01% to about 3% of these products per se or in combination are added to lubricating oils. Other additives such as pour point depressors, viscosity index improvers, thickeners, etc.,'may be added to the lubricating oils in combination with the phosphorus sulfide-aromatic hydrocarbon reaction product and/or the neutralized reaction product.

In addition to their use in lubricating oils, the phosphorus sulfide-aromatic hydrocarbon reaction products and/or the neutralized products thereof are suitable for use in other petroleum Asan' products such as insulating oils, white oils, and

greases, to increase the resistance thereof to oxidation, sludging and the like.

We claim:

1. A lubricant comprising a mineral lubricating oil and a small amount of a neutralized phosphorus and sulfur-containing reaction product or a phosphorus sulfide and an aromatic hydrocarbon.

2. A lubricant comprising a mineral lubricating oil and a small amount of a potassium-com taining neutralized phosphorus and sulfur-containing reaction product of phosphorus pentasulfide and an aromatic hydrocarbon.

3. A lubricant comprising a mineral lubricating oil and a small amount of a sodium-containing neutralized phosphorus and sulfur-containing reaction product of phosphorus pentasulfide and an aromatic hydrocarbon.

4. A lubricant comprising a mineral lubricating oil and a small amount of a calcium-containing neutralized phosphorus and sulfur-containing reaction product of phosphorus pentasulfide and an aromatic hydrocarbon.

5. The method of inhibiting the formation of deposits of the type of sludge, carbon and varnish in an internal combustion engine during use comprising lubricating said engine with a lubricant comprising a mineral lubricating oil normally susceptible to deterioration and a small amount of a phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an aromatic hydrocarbon neutralized with a basic reagent containing a metal constituent.

6. The method as described in claim 5 in which the neutralized product contains potassium.

'7. A lubricant comprising a mineral lubricating oil and a small amount of a phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an aromatic hydrocarbon neutralized with a basic reagent containing a metal constituent, said neutralized reaction product containing the metal constituent of said basic reagent.

8. A lubricant comprising a ing oil and a small amount of a metal-containing and phosphorus and sulfur-containing neutralized reaction product of a phosphorus sulfide and an aromatic hydrocarbon.

9. A lubricant as described in claim 8 in which the metal is an alkali metal.

10. A lubricant as described in claim 8 in which the metal is an alkaline earth metal.

11. A new composition comprising a hydrocarbon oil and a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an aromatic hydrocarbon.

12. A new composition as described in claim 11 in which the neutralized reaction product contains a metal constituent.

13. A new composition as described in claim 11 in which the neutralized reaction product contains an alkali metal constituent.

14. A new composition as described in claim 11 in which the neutralized reaction product contains potassium.-

15. A new composition as described in claim 11 in which the neutralized reaction product contains sodium.

16. A new composition mineral lubricatas described in claim 11 in which the neutralized reaction product contains an alkaline earth metal constituent.

17. A new composition as described in claim 11 t in which the neutralized reaction product contains calcium.

CLARENCE M. LOANE. JAMES W. GAYNOR. 

